From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760864AbZEOE35 (ORCPT ); Fri, 15 May 2009 00:29:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756233AbZEOE3e (ORCPT ); Fri, 15 May 2009 00:29:34 -0400 Received: from hera.kernel.org ([140.211.167.34]:41561 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755748AbZEOE3d (ORCPT ); Fri, 15 May 2009 00:29:33 -0400 From: Tejun Heo To: JBeulich@novell.com, andi@firstfloor.org, mingo@elte.hu, linux-kernel-owner@vger.kernel.org, hpa@zytor.com, tglx@linutronix.de, linux-kernel@vger.kernel.org Cc: Tejun Heo Subject: [PATCH 5/5] x86: ensure percpu remap doesn't consume too much vmalloc space Date: Fri, 15 May 2009 13:28:59 +0900 Message-Id: <1242361739-21186-6-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.6.0.2 In-Reply-To: <1242361739-21186-1-git-send-email-tj@kernel.org> References: <1242361739-21186-1-git-send-email-tj@kernel.org> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Fri, 15 May 2009 04:29:10 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On extreme configuration (e.g. 32bit 32-way NUMA machine), remap percpu first chunk allocator can consume too much of vmalloc space. Make it fall back to 4k allocator if the consumption goes over 20%. [ Impact: add sanity check for remap percpu first chunk allocator ] Signed-off-by: Tejun Heo Reported-by: Jan Beulich Cc: Andi Kleen Cc: Ingo Molnar --- arch/x86/kernel/setup_percpu.c | 18 +++++++++++++++--- 1 files changed, 15 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index 29be178..1f28574 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -169,9 +169,21 @@ static ssize_t __init setup_pcpu_remap(size_t static_size, bool chosen) return -EINVAL; } - /* on non-NUMA, embedding is better */ - if (!chosen && !pcpu_need_numa()) - return -EINVAL; + if (!chosen) { + size_t vm_size = VMALLOC_END - VMALLOC_START; + size_t tot_size = num_possible_cpus() * PMD_SIZE; + + /* on non-NUMA, embedding is better */ + if (!pcpu_need_numa()) + return -EINVAL; + + /* don't consume more than 20% of vmalloc area */ + if (tot_size > vm_size / 5) { + pr_info("PERCPU: too large chunk size %zuMB for " + "large page remap\n", tot_size >> 20); + return -EINVAL; + } + } /* * Currently supports only single page. Supporting multiple -- 1.6.0.2